title: Quantitative Immunohistochemistry of Desmosomal Proteins (Plakoglobin, Desmoplakin and Plakophilin), Connexin-43, and N-cadherin in Arrhythmogenic Cardiomyopathy: An Autopsy Study.
abstract: BACKGROUND
  Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetic disorder related to mutations in desmosomal proteins. The current study tests the hypothesis that immunohistochemical staining for desmosomal proteins is of diagnostic utility by studying autopsy-confirmed cases of ARVC.
  
  
  RESULTS
  We studied 23 hearts from patients dying suddenly with ARVC. Control subject tissues were 21 hearts from people dying from non-cardiac causes (n=15), dilated cardiomyopathy (n=3) and coronary artery disease (n=3). Areas free of fibrofatty change or scarring were assessed on 50 sections from ARVC (24 left ventricle, 26 right ventricle) and 28 sections from controls. Immunohistochemical stains against plakoglobin, plakophilin, desmoplakin, connexin-43, and N-cadherin were applied and area expression analyzed by computerized morphometry. Desmin was stained as a control for fixation and similarly analyzed. The mean area of desmin expression was similar in controls and ARVC (86% vs. 85%, p=0.6). Plakoglobin expression was 4.9% ± 0.3% in controls, vs. 4.6% ± 0.3% in ARVC (p=0.3). Plakophilin staining was 4.8% ± 0.3% in controls vs. 4.4% ± 03% in ARVC (p=0.3). Desmoplakin staining was 3.4% in controls vs. 3.2 ± 0.2% in ARVC (p=0.6). There were no significant differences when staining was compared between right and left ventricles (all p > 0.1). For non-desmosomal proteins, the mean area of connexin-43 staining showed no significant difference by presence of disease.
  
  
  CONCLUSIONS
  The small and insignificant decrease in junction protein expression in ARVC suggests that immunohistochemistry is not a useful tool for the diagnosis.
authors.affiliation: Escola Paulista de Medicina/UNIFESP, Sao Paulo, Brazil.
authors.forename: Fabio
authors.initials: F
authors.lastname: Tavora
authors.forename: Mingchang
authors.initials: M
authors.lastname: Zhang
authors.forename: Nathaniel
authors.initials: N
authors.lastname: Cresswell
authors.forename: Ling
authors.initials: L
authors.lastname: Li
authors.forename: David
authors.initials: D
authors.lastname: Fowler
authors.forename: Marcello
authors.initials: M
authors.lastname: Franco
authors.forename: Allen
authors.initials: A
authors.lastname: Burke
keywords: ARVC; arrhytmogenic cardiomyopaty; autopsy.; sudden death